Fuel injection apparatus in an internal combustion engine

ABSTRACT

Fuel metering apparatus includes a variable venturi and an airfuel mixture ratio control system variable for a plurality of throttle settings.

United States Patent 1 Cinquegrani 1 Jan. 16, 1973 [54] FUEL INJECTIONAPPARATUS IN AN INTERNAL COMBUSTION ENGINE [76] Inventor: Vincent J.Cinquegrani, 333 West Second St., Scottsdale, Ariz. 85251 22 Filed:July30, 1971 [21] Appl.No.: 167,627

[52] US. Cl. ....l23/139 AW, 123/119 R, 123/139 E, 123/140 MP, 123/140FG, 123/140 MC [51] Int. Cl ..F02m 39/00, F02m 31/12, F02d 1/08 [58]Field of Search. .,l23/l39 E, 139 AW, 140 MP, 123/140 FG,140 MC, 119R,32EN, 32 AB [56] References Cited UNITED STATES PATENTS 1,835,61512/1931 Robert ..123/139 AW 2,442,399 6/ l 948 Chandler 2,687,123 8/1954Parsons ..:.l23/l39 AW FUEL PUMP con/r202 AMPLIFIERS FOREIGN PATENTS ORAPPLICATIONS Primary ExaminerWendell E. Burns Attorney-H. Gordon Shieldset al.-

[57] ABSTRACT Fuel metering apparatus includes a variable, venturi andan air-fuel mixture ratio control system variable for a plurality ofthrottle settings.

54 Claims, 7 Drawing Figures 3/1960 France ..123/139 E FUEL INJECTIONAPPARATUS IN AN INTERNAL COMBUSTION ENGINE BACKGROUND OF THE INVENTION 1Field of the Invention This invention relates to an internal combustionengine and more particularly to apparatus for providing a mixture offuel and air in a predetermined ratio in an internal combustion engine.

2. Description of the Prior Art Fuel injection systems are generallyconcerned with the delivery of a mixture of fuel and air in the properratio into a chamber where combustion, the ignition of the fuel and airmixture, takes place. The sequential delivery of a proper quantity, andof a proper or predetermined ratio, of fuel and air into a plurality ofcombustion chambers or cylinders in an internal combustion engine hasbeen a primary objective for fuel injection systems since soon after theinvention of the internal combustion engine.

There are two primary-means for forming a combustible charge, namely,carburetion and fuel injection. In carburetion charge forming, aquantity of fuel is mixed with a quantity of air in a predeterminedratio according to air flow, and the fuel-air mixture is then introducedinto a manifold, or a plurality of manifolds from where the atomizedfuel-air mixture or charge is drawn into the individual cylinders. Dueto the design configurations of the manifolds, the inertia of the fuelmolecules as compared to the air molecules, and the various distancesfrom the carburetor to the individual cylinders, the charge taken intoeach of the cylinders usually varies both quantitatively andqualitatively. That is, the total volume of the charge varies fromcylinder to cylinder and the fuel-air ratio varies from cylinder tocylinder. Moreover, since the metering of the fuel is determined by airflow, the fuel and air ratios are usually not correct over a wide rangeof speed and load conditions.

Fuel injection charge forming provides for the direct injection of apredetermined quantity of fuel to a quantity of air into a manifold ator adjacent to a cylinder, thus insuring substantially equal quantitiesof fuel and air in substantially the same ratio at each cylinder. Themetering ofthe fuel in a fuel injection system is usually governed orcontrolled by some parameter or parameters other than air flow.

A problem of prior art fuel injection systems has been the provision ofmeans for varying the fuel-air ratio accurately over a wide range ofoperating conditions demanded of an engine. For example, an engine isrequired to operate at an idling speed and at various other speed andload conditions and under .various acceleration and decelerationrequirements. There are optimum or desired fuel-air ratios for variousoperating speeds, and there may be an optimum or a minimum amount of airrequired to properly atomize the fuel for proper combustion for thevarious operating speed and load conditions of the engine.

The various embodiments of the present invention, as disclosed andclaimed herein, provide for the proper fuel air ratios under a widerange of speed'and load conditions imposed on an internal combustionengine.

SUMMARY OF THE INVENTION This invention'comprises fuel injectionapparatus for an internal combustion engine. A variable venturi providesfor the volumetric control of air into the engine and also for themetering of fuel through a fuel metering system into the engine. Thefuel-air ratio is predeterrninably variable for a plurality of throttlesettings, permitting the fuel metering system to provide fuel to theengine in accordance with operating demands of the engine andvolumetrically for best engine efficiency.

Included among the objects of the present invention are the following:

to provide a new and useful fuel injection system for an internalcombustion engine;

to provide new and useful apparatus for metering fuel;

to provide new and useful variable venturi apparatus for controlling theflow of air in an internal combustion engine;

to provide new and useful apparatus for injecting fuel in an internalcombustion engine;

to provide new and useful apparatus .for controlling the flow of fuel inan internal combustion engine;

to provide new and useful apparatus for controlling the flow of air inan internal combustion engine; and

to provide new and useful apparatus for controlling the air-fuel ratioin an internal combustion engine.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a schematic representation ofan embodi-.

ment of the fuel injection apparatus of the present invention;

FIG. 2 is a schematic sectional illustrating an embodiment of fuelmetering apparatus of the present invention; I

FIG. 3 is another embodiment of fuel metering apparatus of the presentinvention;

FIG. 4 is another embodiment of fuel metering apparatus of the presentinvention;

FIG. 5 is a schematic representation illustrating another embodiment ofthe fuel injection system of the present invention; FIG. 6 is anotherembodiment of fuel metering ap-' paratus used in the present invention;and

FIG. 7 is a view taken along 7-7 of FIG. 6.

DESCRIPTION OF THE PREFERRED EMBODIMENT FIG. 1 discloses an embodimentof the fuel injection system which comprises the present invention.Broadly speaking, the fuel injection system comprises a fuel meteringsystem, a variable orifice system which cooperates with the fuelmetering system, and a variable venturi system for providing a variableamount of air according to the needs of the engine.

Fuel for the system originates with a fuel supply 10 and from the fuelsupply it flows through a conduit 11 to a variable speed fuel pump 12.The control of the speed of the fuel pump, by fuel pump controlamplifiers 10, is accomplished by a fuel metering system which includessensor units 30 and 50 andfuel pump control amplifiers 2. From the fuelpump 10, the fuel flows through conduit 13 to variable orifice housing20,

which includes a pair of chamber 179 and 180, and an orifice 22 whichseparates the chambers. From the variable orifice housing 20, the fuelflows through another conduit 25 to a second fuel pump 26, which isagain a variable speed fuel pump, controlled by the fuel meteringsystem, and through conduit 27 to fuel heater 28, and then throughconduit 29 for delivery to a fuel nozzle 72 within intake manifold 70downstream or below the throttle 74.

A fuel conduit branches from fuel conduit 13 and provides a bypass ofthe variable orifice housing 20. The fuel flows from conduit 15 througha valve body 14 and through orifice 19 into conduit 17 and to thejunction of conduit 17 with conduit 25 prior to flowing through thesecond fuel pump 26. Within valve housing 14 is a needle valve 18 whichis moved in and out of orifice 19 according to movement of bellows 16.The bellows 16 is a sealed unit which is secured at one end to valvebody 14. The other end of the bellows moves according to thefluctuations in the temperature and pressure of the ambient air. Needlevalve 18 is secured to the movable wall of bellows l6 and its positionwithin orifice 19 accordingly varies with the movement of the bellowsand in accordance with fluctuation in the temperature and pressure ofthe ambient air. The needle valve 18 comprises a tapered needle valveand the size of the orifice accordingly varies with the position of theneedle valve 18 within the orifice 19.

Variable orifice housing 20 includes a pair of conduits 21 and 23communicating with chamber 179 and 180, respectively, within the orificehousing on opposite sides of the orifice 22, which will be described indetail below. The orifice 22, movable within housing 20, divides theinterior of the housing into the two chambers, 179 and 180. Sensor unit30 receives a flow of fuel through conduit 21 and sensor unit 50receives a flow of fuel through conduit 23. The flow of fuel fromchamber 179 to sensor unit 30 and from chamber 180 to sensor unit 50 isproportional to the fuel flow across the orifice 22. This flow isdirectly related to the pressure differential across the orifice asmanifested within sensor units 30 and 50. The sensor units 30 and 50 areshown in block form in FIG. 1 and are disclosed in detail in FIG. 2.

Sensor units 30 and 50 are of substantially the same size and aresubstantially the same with respect to their design. However, theyfunction just the opposite from each other with respect to the sensingof the fuel flowing therein and to the control of the fuel output of thepumps 12 and 26 towhich they are respectively connected. Sensor unit 30is electrically connected to fuel pump control amplifiers 2 byconnectors 3 and 4 and sensor unit 50 is similarly electricallyconnected to the fuel pump control amplifiers 2 by connectors 5 and 6.The amplifiers for the two units are similar in design but, as will beexplained more in detail later, function opposite from each other withrespect to the balancing of the fuel flow across orifice 22 and withinthe sensor units and of the fuel pumps to which the metering units areelectronically connected and which they control. The fuel flow in thesensor unit 30, and therefore the sensor unit 30 and amplifiers in fuelpump control amplifiers 2 control the output of fuel pump 12 and thefuel flowing in the sensor unit 50, and accordingly, the unit itself andits amplifiers, is electronically connected to and controls the outputof fuel pump 26.

Both sensor units 30 and 50 communicate with the interior of thevariable orifice housing 20. Since the sensor units are on oppositesides of the orifice within the housing 20, and since the sensor unitsare directly above the housing and are of substantially the same sizeand same height, the flow of fuel within the sensing units is anindication of the fuel flowing across the orifice. Since the fuel flowacross the orifice can be measured or can be indicated by the sensingunits, it is accordingly possible to control the fuel flow through theorifice according to the fuel flow within the sensor units. This isaccomplished by having sensor unit 30 tions of substantial equillibriumwith respect to speed and load on the engine, both fuel pump 12 and fuelpump 26 would be flowing the same amount of fuel.

However, upon demand from the engine either with respect to load or withrespect to speed, and accordingly whether accelerating or decelerating,the fuel pumps would at least momentarily be out of balance with respectto their individual outputs according'to the fuel flow across theorifice as indicated by the fuel fiow to the sensor units 30 and 50.This will be explained in detail with reference to FIG. 2.

In FIG. 2 the sensor unit 30 includes a housing 31 which is preferablycylindrical in configuration. Within the housing is a float 32, theposition of which within the housing 31 depends on the amount of fuelflowing into the housing by way of conduit 21 from chamber 179 oforifice housing 20. The float 32 moves up and down, according to thefuel within the housing, on guide rod 33 which is located within acentral bore 34 of the float. The float 32, at its lower position, asshown in FIG. 2, rests on interior shoulder 35 on the bottom portion ofthe housing 31. The lower wall 36 of the housing 31 is situated belowthe shoulder 35 and it includes a plurality of orifices 37 through whichfuel flows from conduit 21 to the interior of the housing 31. Guide rod33 is secured to lower end wall 36. The housing 31 is closed 'at its topby upper end wall 38. Disposed through an aperture in the upper end wall38 is a light source 40. Lightsensitive means, such as photo cell 42,are located adjacent light source 40 I through an aperture in thehousing 31. The float 32 includes a float cavity 44 on the interiorthereof, and it also includes a top flange 46. The top flange extendsabove the body of the float in the manner of an inverted piston skirt.The float 32 is not in a tight fitting relationship with respect to theinterior of the housing 31, but for accuracy and ease of movement of thefloat accord ing to the flow of the fuel within the housing, it is'in arather loose or sloppy fitting relationship with respect to the interiorof the housing 31.

In operation, the light source 40 is illuminated by an appropriatecurrent through conductor 4 and the fuel pump control amplifierswhenever the ignition switch of the internal combustion engine is turnedon. The light sensitive means or photocell 42 is responsive to theillumination produced by the light source 40 for the determination of avoltage output therefrom. As fuel flow from variable orifice housingthrough conduit 21 to the interior of the sensor unit housing 31increases, the float rises within the interior of the housing. As thefloat rises, the skirt or flange 46 is disposed between the light source40 and the light sensitive means or photo cell 42, thus depriving thephoto cell of a portion of the illumination from the light source. Theextent to which the photo cell is deprived of illumination variesaccording to the position of the float and of the flange 46 thereof. Asthe flange 46 is raised in height, thus depriving the photo cell ofillumination, the voltage output from the photocell 42 decreases. Thisdecreasing output voltage is sensed by the fuel pump control amplifiersthrough conductor 3 and a signal is transmitted to fuel pump 12 throughconductor 7 (see FIG. 1) causing the fuel pump to decrease its speed andconsequently its output. As the fuel flow to the interior of the housingdecreases, the float 32 will move down within the housing, thus removingthe flange 46 from between the light source and the light sensitivemeans 42, which increases the output voltage of the light sensitivephoto cell 42. The increasing voltage from the photo cell in turnsignals the fuel pump 12 to increase its speed and accordingly toincrease its output.

The operation of sensor unit 50 is just the reverse, while theconstruction is substantially identical. Sensor unit 50 includes ahousing 51 with a float 52 located on the interior of the housing in aloose fitting relationship thereto. The float 52 is located within thehousing and floats on the fuel which flows to the housing from conduit23 from chamber 180 in the interior of the variable orifice housing 20.A guide pin 53 in located within a central bore 54 of the float 52. Acavity 64 is located on the interior of the float 52. An interior lowershoulder 55 is located at the bottom of the housing adjacent a lowerwall 56. The lower wall 56 includes a plurality of apertures 57 whichcommunicate with the interior of the housing 51. An upper wall 58includes a light source 60 extending through an aperture in the upperwall and a light sensitive means or photo cell 62 is located adjacentthe light source 60 through an aperture in the housing 51. The float 52includes an upper flange or skirt 66 which, depending on the location ofthe float within the housing 51, decreases the illumination from thelight source 60 to the light sensitive means 62. Light source '60receives power through conductor 6. Conductor 6 provides power for lightsource 60.

In operation, the position or location of the float 52 within thehousing 51 is determined by the flow of the fuel from chamber 180 in thevariable orifice housing 20 through conduit 23 and through the apertures57 of the lower housing wall 36 to the interior of the housing 31. Asthe flow of fuel within the housing increases, the float 52 is lifted onthe guide rod 53 and the flange 66 is disposed between the light source40 and the photo cell 62. As the skirt of flange 66 moves upwardly andextends between the light source and the photo cell, the decreasingvoltage output of the photo cell causes the speed of fuel pump 26 toincrease. Conversely, as the fuel flow across orifice 22 and within thehousing 51 decreases, and the float accordingly is lowered within thehousing, more light from the light source 40 strikes the photo cell 62as the flange 66 is lowered and the voltage output from the photo cellthrough conductor 4 to the fuel pump control amplifiers 2 increases. Theincreased output results in a signal through conductor 8 to the fuelpump 26 to decrease its output.

When the level of the fuel within the housings 31 and 51 is the same,the output of the fuel pumps, resulting from them operating at about thesame speed, is substantially the same and the system is in equilibrium.At such time as there is an increase or a decrease in the demand for thefuel from the engine, the two metering units will be in a state ofimbalance, resulting in a change in the respective outputs of the fuelpumps, until such time as the system is once again in equilibrium. Astate of equilibrium with respect to the output of the fuel pumps canexist at any output from a very low output to a very high output, andsuch state is determined by the demand of the engine.

Reference will again be made to FIG. 1. From fuel pump 26 the fuel flowsto fuel heater 28 by way of conduit 27. The heater 28 may be of anydesign, but is preferably fueled from a source separate and apart fromthe engine itself. That is, rather than to use exhaust gases as the heatsource for the fuel heater or preheater, it is preferable to have aseparate heating source or element, which could be electrical, but ispreferably either a butane or propane type heater. The purpose of theheater 28 is to heat the fuel flowing therethrough to the extent thatthe fuel is substantially vaporized prior to delivery to fuel nozzle 72via conduit 29. The nozzle 72, as previously mentioned, is locatedwithin intake manifold 70 downstream from or below throttle 74.

The vaporization of the fuel by the heater 28 insures proper mixturewith the air flowing through the intake manifold prior to delivery ofthe fuel and air mixture into the cylinders and also reduces the amountof unburned gases and other pollutants from the engine. With the fuel atits full extent of vaporization prior to delivery into the intakemanifold, the fuel is assured of combustion to a greater extent thanwith fuel entering into the intake manifold in either a partial state ofvaporization or in a liquid or a fuel droplet state.

Above the throttle, or upstream, with respect to air flow, from thethrottle 74, and within intake manifold I across the orifice 22 isdirectly affected by the vacuum 70, is a venturi 76. A vacuum line 78senses the pressure or the extent of the vacuum at the throat of 'theventuri and provides a means for transmitting the pres- I sure or vacuumof the venturi to other parts of the fuel injection system. The vacuumline or conduit 78 extends between the throat of the venturi to sensorunit 50 where it introduces the vacuum or the low pressure at theventuri 76. v

A conduit 79 branches from conduit 78 for delivery within variableventuri system 80. The variable'venturi system 80 includes a venturipiston 82, which is of a generally conical configuration, and it extendsinto the venturi 76. The venturi piston 82 is fastened to a piston rod83 which extends through a wall of the intake manifold 70 and into acylinder or housing 85. Within the housing or cylinder 85 is anactuating piston 84 secured to the piston rod 83. The head of thecylinder or housing 85 comprises an end wall 86 with an aperture or boreextending therethrough in which the piston rod 83 moves. The lower endwall of the cylinder or housing 85 is the wall of the intake manifold70. Exterior of the cylinder head or end wall 86 and fastened to thepiston rod 83 is a cam plate 88 which includes a plurality of adjustablecam screws 89 extending therethrough. The cam screws may be adjusted asdesired and as the piston rod 86 moves, the plate and screws movetherewith. If desired, a fixed cam could be used instead of theadjustable screws. The vacuum lines 78 and 79 introduce the vacuumpressure from the throat of the venturi to the interior of the cylinderor housing 85 above the actuating piston 84. It will thus be seen thatthe movement of piston 84, and accordingly of piston rod 83 securedthereto and venturi piston 82' also secured to rod 83, depends on thevacuum at the throat of the venturi. When the vacuum at the throat ofthe venturi increases, this vacuum or low pressure is transmitted tocylinder 85 by conduits 78 and 79 and serves to draw the piston 84 tothe left, as shown in FIG. 1, which in turn withdraws venturi piston 82out of the venturi. With the venturi piston withdrawn from the venturi,more air flows around the piston and through the venturi and on into theintake manifold for delivery to the cylinders after mixing with theatomized fuel delivered through nozzle 72. As the engine demands fueland air, the manifestation of that demand by means of air flow throughthe venturi 76 is transmitted to the variable venturi system which inturn provides for the precise metering of the air according to thedemands of the engine. When the air flow through the venturi decreases,the pressure increases, that is, the vacuum decreases, and pressurewithin cylinder 85 increases and piston 84 is biased by compressionspring 87 to move the piston rod and the venturi piston into the throatof the venturi. Air enters above the venturi via air intake chamber 71,which may include an air filter. Cylinder 85 is vented to the chamber 71through opening 81 below piston 84.

Another conduit 91 branches from vacuum conduit 78 and connects with avalve body 92. The valve body 92 has attached thereto a sealed bellowsunit 94. The bellows unit, while sealed at one wall to the valve body92, includes a lower movable wall to which is secured, on the interiorof the bellows, a tapered needle valve 95. The needle valve extends intoan orifice 96 within the valve body 92 and thus the position of theneedle valve 95 within the orifice 96 controls or governs the vacuumpressure therethrough.

A conduit 98 extends from the valve body 92 below the orifice 96 andconnects with a conduit 99 which extends from the air intake chamber 71upstream from both the throttle and the variable venturi to the sensorunit 30 above the float therein. Since the air conduit 99 is upstream orabove the throttle and the variable venturi, the air flowing through theconduit is at substantially atmospheric pressure. The atmosphericpressure thus flowing to the sensor unit 30 provides a balance oratmospheric air is warm, the sealed bellows unit 94 expands andwithdraws the tapered needle valve from the orifice 96, which allowsvacuum pressure from the throat of the venturi 76 through vacuum line 78and conduit 91 and conduit 98 to be bled into atmospheric air conduit99. This in turn modulates the air above the float 32 in sensor unit 30.This modulation of the atmospheric air pressure within sensor unit 30provides a lower pressure area within the unit and thus serves todecrease the flow of fuel between the sensor units across the orifice 22by decreasing the pressure differential within the sensor units. This isaccomplished by the raising of the float and the skirt 46 within theunit 30 which causes a decrease in the light reaching the photo cell 42from light source 40. This results in the decrease of the output fromthe photo cell which in turn results in the decrease in the output ofthe fuel pump 12. When the atmospheric air temperature is cold, thereverse takes place. That is, the bellows contract and the needle valveseals off the orifice which prevents vacuum from conduit 78 fromreaching con- I duit 99 and accordingly provides only atmospheric airpressure within sensor unit 30.

' The flow of fuel across the orifice 22, and hence the flow of fuel tonozzle 72, is directly related to the pressure differential across theorifice as manifested by the pressure differential across or between thesensor units 30 and 50. With air at atmospheric pressure, modulated byengine vacuum at sensor 30, and with air at the pressure of the intakemanifold vacuum at sensor 50, there is a sufficient differential tocause a flow of fuel across the orifice 22 between the sensors. The flowof fuel is detected by the sensor units and the fuel pump controlamplifiers 2 which in turn signal the fuel pumps 12 and 26 to increaseor decrease their output.

The fuel pumps respond to the commands of the sensors through conductors3 and 5 to the fuel pump control amplifiers 2 and through conductors 7and 8 to the fuel pumps, respectively, to equalizethe fuel flow. Thefuel flow is responsive to air flow through venturi 76. The venturipressure, or vacuum, therefore controls the fuel flow by controlling thepressure differential across orifice 22. 1

The orifice 22 is variable in two ways. The first manner of variabilityis that a tapered needle valve or metering rod 24 is movable within theorifice 22. The second manner in which the orifice is variable is thatthe orifice is itself movable within the orifice housing 20.

The tapered metering rod 24 is moved within the orifice 22 by mechanicallinkage from the movement of the venturi piston 82.The piston rod 83 towhich the venturi piston 82 is secured includes, as has been described,a cam plate 88 which includes a plurality of adjustable cam screws 89.As the venturi piston 82 and the piston rod 83 move in response to thevacuum at the throat of venturi 76, there is cooperating movement withthe metering rod actuation system 140. The movement of piston rod 83moves the c am plate 88 with the adjustable screws 89 thereon againstthe metering rod actuation system 140 to move the tapered metering rod24 in the orifice 22. The adjustable cam screws 89 sequentially bearagainst cam 141 as the rod 83 moves. The earn 141 is pivotally securedto a rod 142 which is in turn connected to a flexible shaft 144. Theshaft 144 is in turn secured to the metering rod 24 through a connection145 on one end of the variable orifice housing 20. A compression spring146 biases the cam 141 and the rod 142 secured thereto against theadjustable screws 89. The spring 146 serves also to bias the meteringrod 24 out of the orifice 22. The sequential action of the adjustablescrews, as the cam plate 88 is moved by the piston rod 83, serves tomove the rod 142 and the flexible shaft 144 against the bias of thespring. By adjusting the plurality of screws 89, the size of the orifice22 is varied to richen the mixture as desired. For example, as the airflow through the orifice 76 increases, the vacuum at the throat of theventuri increases and the venturi piston 82 is withdrawn from the throatof the venturi to increase the flow of air therethrough. As the pistonis withdrawn the cam plate 88 moves with the piston rod and the venturipiston and the adjustable screws 89 sequentially bear against cam 141.As shown in. the drawing, as the piston rod is moved to the left to movethe venturi piston out of the orifice, the bias of the spring 146 willmove the cam 141 upwardly against the screws 89 to withdraw the meteringrod 24 out of the orifice 22. The movement of the metering rod out ofthe orifice will allow more fuel to flow through the orifice 22 andthrough conduit 25 to fuel pump 26 and through conduit 27, through fuelheater 28, conduit 29, and through nozzle 72 into the manifold 70, thusriche'ning the mixture in a controlled amount according to the flow ofair through the manifold and in accordance with the demand of theengine.

The cam 141 is pivotally connected to the rod 142 and, due to thepivoting of the cam and to the curvature of its camming surface, themetering rod 24 is also responsive to engine temperature for adjustmentinto or out of the orifice 22. This actuation is accomplished by meansof a bellows 150 which is in turn responsive to the temperature of theengine for its expansion or contraction. A movable wall 152 of thebellows is mechanically connected through rod 148 to the cam 141. Asshown, the rod 148 is bent or configured to impart movement to themetering cam 141 directly with the movement, by .expansion orcontraction, of the bellows 150. The metering rod actuation system,including the cam and the rod 142, spring 146, and shaft 144,'as well asthe bellows 150 and a the rod 148 movable thereby, are securedto a plateor bracket 155 which may be conveniently secured to any part of theengine. The bellows 150 is conveniently connected to an enginetemperature sensing bulb or any other source of engine heat by anappropriate conduit or manifold 154. In operation, when the engine iscold the bellows 150 is contracted and the rod 148 pivots the earn 141slightly causing the adjustable screws to-contact the cam on a differentcammingsurfaee. This causes amovement of the shaft 144 and rod 142 tomove the needle valve 24 slightly out of the orifice 22 which in turnresults in a slightly richer mixture. As the engine heats up, thebellows expands which results in movement of the wall 152 of the bellowsand of the rod 148 connected fuel needle valve which is responsive toboth the tem-- perature of the engine and to the flow of air in the airintake manifold according to the settings of the adjustable screws 89.The number of the screws and their individual settings may be as desiredin order to compensate for the linear movement of the venturi piston inthe venturi. Or, as previously indicated, a solid camming surface,contoured as desired, could be used.

The movement of the orifice 22 within the orifice housing 20 isaccomplished in response to the load on the engine as manifested by thepressure inside the intake manifold 70 below thethrottle plate 74. Theload responsive orifice movement system includes a housing 162 and ahousing cover plate 164 secured thereto. An aperture 166 in the housingcover plate 164 admits air at ambient pressure inside the'cover plate. Aflexiblediaphragm 168 is secured at its outer periphery between matingflanges on the housing 162 and the housing cover plate 164. Thediaphragm 168 is clamped between a diaphragm plate 170 and a diaphragmplate 171 at a central portion of the diaphragm. The diaphragm plates170 and 171 may be secured together, and in turn may secure diaphragm168 therebetween, by any appropriate fastening means. The diaphragmplate 170 is secured to a rod 172 which is in turn connected to theorifice 22. Apertures 176 provide communication between chamber 179 onthe interior of the orifice housing 20 and the orifice 22. The orifice22 is located and is movable within interior bore 178 of the orificehousing 20. v

A compression spring 174 extends about the rod' 172 within one of theexpansible chambers defined by the housing and the diaphragm,specifically between an end wall of the housing 162 and the diaphragmplate 170. The spring .urges the rod 172 to move the orifice 22 to theleft as shown in FIG. 1, which results in the movement of the orifice 22away from the tapered metering rod 24. This results in an increase inthe flow of fuel from chamber '179- through apertures 176 and throughorifice 22 into chamber 180, and ultimately results in an increase inthe fuel delivered to nozzle 72. As the vacuum within the intakemanifold 70 increases, or as the load imposed on the engine decreases,the intake manifold vacuum through conduit increases within the housing162 and moves the diaphragm 168 and the diaphragm plate 170 and 171, andthe rod 172 connected thereto against the bias of the spring 174 to movethe orifice to the right, as shown in FIG. 1. Relative motion is thusprovided between the orifice and the tapered rod therein and results ina decrease in fuel between chamber 179 and chamber 180 andlthusultimately results in a decrease in the amount 0f fuel delivered tonozzle 72. Atmospheric pressure in one exthe diaphragm, are balancedagainst the bias of the spring to move the orifice within the orificehousing.

Associated with the movement of fuel through orifice 22 between chamber179 and 180 is a corresponding flow of fuel in conduits 21 and 23 to thesensor units 30 and '50, respectively. That is, as the flow of fuelbetween the chambers 179 and 180 through the orifice 22 varies, so alsodoes the fuel flow vary through conclosed in FIG. 3 rather than the twounits as. shown in FIG. 2. The reasoning is, of course, that the unitsare substantially the same in construction, even though with respect tooperation or to the signals emanating therefrom to the amplifiers and tothe fuel pumps which they control, each sensor unit operates oppositelyfrom the other one. In FIG. 3 a radio frequency sensor unit is shown.The unit includes a housing 101 which includes a float chamber 102therein. A float 103, which is preferably made of a conductive metal, isshown resting on an interior lower shoulder 104 of the housing 101. Alower opening 105 connects the housing 101 with the interior of theorifice housing by means of a conduit such as either 21 or 23 of FIG. 1.An upper opening 106 may be connected to a source of atmospheric airpressure, modulated if so desired, as shown in FIG. 1 through conduits98 and 99, or to a source of venturi vacuum, as by conduit 78 of FIG. 1,according to its particular use. Fuel flows through the opening 105 andinto the float chamber 102 and lifts the float from the shoulder 104. Aradio frequency coil 108 is shown schematically wound about the housing101. The coil 108 may be connected to any well known radio frequencytype amplifier. The position of the float within the housing can besensed by the amplifier connected'to the coil 108. In this manner, asignal, corresponding to the output of the photo sensitive means 42 and62 of FIG. 2, which varies according to the location or position offloat 103 within the housing 101', can be used to control the speed offuel pumps 12 and 26 of FIG. 1. As with the system described accordingto 7 FIGS. 1 and 2, the pressuredifferential between the I floatchambers determines the actual fuel flow across the orifice and thesensor units, with the fuel pump control amplifiers, control or balancethe output of the fuel pumps.

FIG. 4 discloses another embodiment of a sensor unit which may be usedin the environment of FIG. 1. Again, as with respect to FIG. 3, only asingle unit is disclosed in FIG. 4. It is, however, understood that apair of such units may be used, such as disclosed in FIG. 2, in theenvironment of FIG. I.

The sensor unit comprises a housing or cylinder 111 which includes alower end wall 112 and an upper end wall or cylinder head 114. Anopening or aperture 113 is located in the lower end wall 112 and servesto communicate by means of an appropriate conduit, such as 21 or 23 ofFIG. 1, with a chamber within the interior of orifice housing 20. Thefuel from within the orifice housing 20, thus flows through a conduitand through aperture 113 to the interior of the cylinder or housingnicates with either vacuum pressure via a vacuum line such as 78 of FIG.1, or with a balance line such as conduit 99, which provides air atsubstantially atmospheric pressure, vacuum modulated, if desired, to theinterior of the housing 111. Whether vacuum or atmospheric pressure isadmitted to the interior of the housing 111 depends on the use of theunit with respect to the fuel pump which it is tocontrol. An expansiblechamber device, such as expandable bellows unit 116, is secured to thelower end wall 112 about the aperture 1 13 so as to restrict or confinethe fuel flowing through aperture 113 to the interior of the bellows116. The bellows includes a movable end wall-118, the position of whichfluctuates according to the flow of fuel within the bellows throughaperture 113 and according to the pressure on the interior of thehousing 111 about the bellows 116. A rod 116 is secured to movable endwall 118' and the rod supports an opaque partition or shutter 122. Ifdesired, the rod may be omitted and the shutter may be directly securedto the bellows end wall 118. Located. opposite each other in the chamberor cylinder 111 is a light source 124 and light sensitive means, whichmay be a photo cell 126. Power to the light source 124 is by conductor125 from fuel pump control amplifiers, such as disclosed in FIG. l. Oneterminal of boththe light source and the photo cell is illustrativelygrounded, as in FIGS. 1, 2, 5, and 6 with similar and other electricalcomponents, and as is typical of ground return electrical systems inautomotive use. The light source and the light sensitive means functionin substantially the same manner as described with respect to FIG. 2.That is, as the flow of fuel within the bellows 116 varies, the bellowsexpands and contracts and accordingly moves the shutter 122 securedtothe bellows end wall 118 by the rod As the shutter is moved with respectto the light source and to the light sensitive means, the illuminationfrom the light. source varies on the light sensitive means, or photocell, and the output therefrom is accordingly varied. As with FIG. 2,the output from the photo cell may be received by fuel pump controlamplifiers through conductor 127 and in turn used to control the speed,and'thus the output, of a fuel pump such as fuel pump 12 or fuel'pump26. As previously noted, the pressure I differential betweentheinteriors of a pair of units such as shown'in' pump controlamplifiers are connected to the fuelpump through conductor 207. Fromconduit 213, fuel flows through conduit 215 into a cylinder 216 and fromcylinder 216 through conduit 229 through variable orifice 232 andthrough conduit 239 to fuel heater 240.

The fuel is substantially vaporized by fuel heater 240 and it then flowsthrough conduit 241 to fuel nozzle 242 for delivery into intake manifold254 above the venturi 256 and also above the throttle plate 244.

The purpose of cylinder 216 is to serve as an ac-.

celeration-deceleration pump to either remove fuel or to add fuel uponmovement of the throttle either to the closed or to the open positions.Cylinder 216 includes a cylinder head 218 through which extends a pistonrod 226. At the opposite end of cylinder 216 from the head 218 is acylinder end wall 220. An aperture 222 extends through the end wall 220and vents part of the cylinder to the atmosphere. Secured to one end ofpiston rod 226 is a piston 224. The aperture 222 in end wall 220 ventsthat portion of the cylinder below the piston 224 to atmosphericpressure while the head end of the cylinder above piston 224 is open forthe flow of fuel therethrough. The piston rod 226 extends throughcylinder head 218 and is directly connected to throttle 244 such thatthe opening of the throttle 244 moves the piston on its exhaust strokeso as to cause fuel to flow out of cylinder 216 through conduit 229.This amount of fuel exiting the cylinder by virtue of the movement ofthe piston 224 is greater than the normal flow of fuel through fuelconduit 229 which is due only to the fuel pump 212. A check valve couldbe placed in conduit 215 to prevent a back flow of fuel through conduit215 as piston 224 pumps fuel out of the cylinder 216 and to insure thatthe fuel so pumped flows into conduit 229. The reverse situation alsooccurs as the throttle is closed. The closing of the throttle moves thepiston rod 226, with piston 224 attached thereto away from the pistonhead 218 on the intake stroke and draws fuel from lines 215 and 229 intothe interior of the cylinder 216. The withdrawal of the fuel from theline therefore decreases the amount of fuel going through lines 229,239, and 241, and through nozzle 242 into the engine. The net result ofthis is to decrease the amount of unburned gases, and therefore. thepollutants, from the atmosphere as the engine is decelerated. Suchacceleration-deceleration pump could, of course, also be used with theembodiment of FIG. 1.

From fuel conduit or line 229 the fuel passes through variable orifice232 prior to entering line 239. The variable orifice 232 includes avalve body 230 which includes a needle valve 234 therein. The needlevalve includes a tapered portion which extends into the orifice 232.Movement of the tapered needle valve 234 within the orifice 232 governsthe size of the orifice and thus controls the amount of fuel flowingtherethrough. The tapered needle valve 234 is mechanically connected topiston rod 226 by a rod or link 236, which is connected to pivot 237secured to the valvebody 230. The link or rod 236 is connected at oneend to the needle valve 234 and at its other end to piston rod 226, andits pivots between the two ends on pivot 237. Movement of the throttle244 imparts movement to piston rod 226 which in turn moves the link 236and the needle valve connected therewith. As the throttle 244 is opened,movement of the piston rod 226 withdraws the needle valve from orifice232, allowing more fuel to flow therethrough. As the throttle 244 isclosed, movement of rod 226, which is transmitted through link 236,moves needle valve 234 into the orifice and decreases the flow of fueltherethrough.

14 From fuel line 239 the fuel flows through fuel heater 240 where it issubstantially vaporized, in a manner similar to that described above forfuel heater 28. That is, by use of a heater, such as a propane or butaneheater, the temperature of the fuel is raised-sufficiently to cause thefuel to be vaporized from its liquid state for ultimate transmittal intothe intake manifold in such vaporized state. The more complete thevaporization of the fuel, the more complete is the combustion of the 7fuel air mixture. Thus the vaporizing of the fuel prior to delivery intothe manifold insures more complete combustion which gives greaterefficiency to the engine and Within the venturi 252 is a venturi piston260 which moves into or away from the venturi in response to themovement of the throttle for more or less air flow. As the enginedemands more air, according to the movement of the throttle, the venturipiston 260 is withdrawn from venturi 252 which allows more air to ,flowthrough. Within the upper portion 254 of the intake manifold the aircomes into first contact with the fuel as the fuel exits nozzle 242.Just below, or downstream, from nozzle 242 the fuel and air passesthrough another venturi 256 which serves to increase the mixing or thecombining of the air fuel mixture prior to delivery into lower portion258 of the intake. manifold belowthe throttle 244.

The variable venturi is also controlled by mechanical linkage with theopening and closing of the throttle. The venturi piston 260 moves intoand out of venturi 252 by movement of rod 262 which is connected to theventuri piston 260. The rod or link 262 is pivotally connectedintermediate its ends at pivot 263 which is in turn secured to a portionof the intake manifold 250. At the end of link 262 opposite that whichisconnected to the piston 260, the link is connected to piston rod 226.Accordingly, as the throttle 244 is opened, movement of piston rod 226imparts movement to link or rod 262 which in turn pivots at pivot 263 towithdraw the piston from the venturi. As thethrottle is closed, movementof piston rod 226 in the opposite direction reverses the movement oflink 262 and moves venturi piston 260 into the venturi 252 and decreasesthe flow of air therethrough.

The flow of both fuel and air, through the mechani-' cal linkage abovedescribed, thus controls the flow of air and the flow of fuel accordingto the setting of the throttle to provide the correct fuel air mixtureunder all throttle settings of the engine. In addition to the mechanicallinkage described with respect to the throttle positions and to the flowof fuel and the flow of air, the flow of fuel, with respect to the fuelpump, is independently controlled by sensor unit 270. The sensor unit270 includes a lower housing 272, including a lower end wall 273 throughwhich an aperture extends which connects the housing 272 to fuel conduit213,

and an upper housing 274. a diaphragm276 is secured at its outerperiphery between the lower housing 272 and the upper housing 274 andthus divides the housings into two expansible chambers. The upperhousing includes an upper end wall 275. While the outer periphery of thediaphragm 276 is secured by the housings 272 and 274, the inner portionof the diaphragm is secured, by an appropriate fastening means, betweentwo diaphragm plates, upper plate 277 and lower plate 278. Locatedwithin the lower housing 272 and above the aperture in the lower endwall 273 and thus communicating with fuel conduit 213, is anotherexpansible chamber device, a flexible bellows 281. The bellows includesa movable end wall, remotely located from the aperture in lower end wall273, which is secured to lower diaphragm plate 278. Thus movement of thebe]- lows, either expanding or contracting, results in movement of thediaphragm 276 through diaphragm plates 278 and 277 connected therewith.The diaphragm separates the housings into two chambers, a lower chamber279 within the lower housing 272, and an upper chamber 280 within upperhousing 274.

A vacuum conduit 283 extends between the throat of venturi 252 and lowerhousing 272. The vacuum existing at the throat of the venturi is thussensed through line 283 within the lower housing 272 beneath thediaphragm 276 and exteriorally of the bellows unit 281. The fuelpressure through conduit 213 within bellows 281 causes the bellows toexpand or contact, in accordance with thepressure of the fuel. Thepressure or extent of the vacuum existing within the housing 272 throughline 283 also exerts an influence on the expansion or contraction of thebellows 281. If the vacuum existing at the throat of the venturi ishigh, the pressure existing in chamber 279 within the housing 272 willbe low and will thus tend to urge the contraction of the bellows unit byurging the diaphragm 276 and the plates 277 and 278, to which thediaphragm and the bellows are secured, toward end wall 273. If thevacuum existing at the venturi 252 is low, the pressure existing withinthe housing 272 will correspondingly increase, which in turn will tendto urge the expansion of the bellows unit 281 by movement of thediaphragm and plates away from end wall 273 and towards the upper endwall 275, thus increasing the size of chamber 279 and decreasing thesize of chamber 280.

Vacuum pressure from the throat of venturi 252 through vacuum conduit283 also is transmitted through a branch line or conduit 285 fromconduit 283 through a mixture adjustment valve 286 and conduit 289 toupper chamber 280' above the diaphragm 276 and within the upper housing274. Within mixture adjustment valve 286 is an adjustablerneedle valve288. The needle valve 288 may be adjusted as desired to permit thevacuum pressure to be transmitted to chamber 280. The vacuum pressurethrough conduits 283, 285, needle valve 286 and conduit 289 serves tomodulate the pressure within chamber 280, which is normally atatmospheric pressure through air conduit 293 from air valve 290.

The air valve 290 includes an aperture 291 through which air isintroduced to orifice 292 which is in turn connected to air conduit 293.A movable needle valve 294, which includes a tapered portion, extendsinto orifice 292and the movement of the needle valve in the 16 orificecontrols the flow of air from aperture 291 to conduit 293. The needlevalve 294 is moved by a bellows 296 which is fastened to a cover plate297 of belthe air valve body 290 with the tapered needle valveportion'extending into theorifice 292. The bellows 296 comprises asealed bellows unit and expands and contracts according to thetemperature and pressure of at mospheric air. Accordingly, the airpressure within chamber 280 is modulated according to the temperatureand pressure of the atmospheric air and according to the vacuum existingat the throat of venturi 252 through mixture adjustment valve 286 toeither richen or lean the fuel air mixture, as described in detailbelow.

Secured to the upper diaphragm plate 277 is a rod 302 which supports ashutter 304. (in opposite sides of the upper chamber housing 274 arelight source 306 and light sensitive means, such as photocell 308. Theillumination or light from the light source 306 striking the photo cell308 results in an output from photo cell illumination on photo cell 308,the greater its output.

The shutter 304 serves to block the illumination or light from 306 tophoto cell'308 in varying degrees, depending on its specific location.Movement of the shutter with respect to the light source 306 and photocell 308 is determined by movement of the diaphragm 276 and thediaphragm plates 277 and 278 according to the movement of bellows unit281 and the relative pressures within chambers 279 and 280. In turn thepres sure in chambers 279 and 280 are affected by pressure transmittedto the respective chambers through conduits 283 and 289. Movement ofbellows 281, eitherwith respect to its expansion or its contraction, isdeter mined primarily by the pressure of the fuel in the bellows fromfuel line 213. As the pressure of fuel in the bellows increases, thebellows expands and causes the upward movement of the diaphragm and thediaphragm plates and the shutter, which blocks the'illumination betweenlight source 306 and photo cell 308. This results in a decrease in theoutput from photo cell 308 and the fuel pump control amplifiersaccordingly send a signal to fuel pump 212 through'conductor 207 todecrease the speed and thus the output of fuel pump 212. As the outputof the fuel pump decreases, the

pressure of the flow through line 213 to the bellows 281 and alsothrough conduit 215 and ultimately through the fuel conduits tonozzle242 decreases. If desired,

the rod302 may be omitted and the shutter 304 may be secured directly toplate 277.,

' I .As the fuel pressure in bellows unit 281 decreases,

the movement of the diaphragm plates andultirnately the shutter 304 isin response to the contraction of the bellows 281, which in turn movesthe shutter from between the light source and the photo cell. Thismovement is accompanied by an increased output from photo cell 308 tothe fuel pump control amplifiers through conductor 205 and, in responsethereto, a signal is transmitted through conductor 207 to the fuel pumpto increase the speed thereof and thus the output. The increased outputof the fuel pump in turn means an increase in fuel flow to the nozzle242.

In addition to the control of the fuel pump directly by the movement ofthe bellows, the pressure within chambers 279 and 280 is used toindirectly influence the expansion or contraction of the bellows whichin turn is reflected in an increase ordecrease in the output of the fuelpump. This is accomplished, for example, according to the flow of airthrough venturi 252 and/or by the expansion and contraction of bellows296 according to ambient air temperature and pressure. As air I flowthrough venturi 252 increases, the vacuum at the throat of the venturialso increases, decreasing the pressure in conduit 283 and in turndecreasing the pressure in chamber 279. The decreased pressure inchamber 279 tends to urge the diaphragm downwardly, as shown in FlG. 5,toward the end wall 273 of the lower housing 272 which in turn urges thecontraction of the bellows 281. The contraction of the bellows 281 isaccompanied by an increase in the output of photo cell 308 which in turnresults in a signal to the fuel pump to increase its speed and output..Thus the decreasing pressure within chamber 279, urges or causes thechamber 279 to decrease in size due to the displacement in a downwarddirection of the diaphragm 276.

The opposite result is achieved as the air flow through the throat ofthe venturi 252 diminishes, thus lowering the vacuum at the throat ofthe venturi, or increasing the pressure at the throat of the venturi.The lowering of the vacuum, or the increasing of the pressure, at thethroat of the venturi is sensed within the chamber 279 through theconduit 283. The chamber 279 is thus increased by an upward movement ofthe diaphragm 276 and of the diaphragm plates, the bellows, and theresultant movement of the shutter 304 between the light source 306 andthe photo cell 308. This in turn results in the decreasing output of thefuel pump and a diminishing fuel flow to nozzle 242.

The pressure Within the-upper chamber 280 also is correlated with thespeed of the fuel pump 212 through the movement of the diaphragm 276,rod 302 secured to upper diaphragm plate 277 and shutter 304. Thebellows unit 296 expands and contracts according to atmospheric airtemperature and pressure. When the air temperature is high, the bellowsunit tends to expand and move needle valve 294 into orifice 292, whichdecreases the flow of atmospheric air from aperture 291 to conduit 293and into chamber 280. As the flow of air through orifice 292 isdiminished, the-vacuum from the throat of venturi 252 through conduits283 and 285 and mixture adjustment valve 286 and conduit 289 isincreased to chamber 280. That is, the air through conduit 293 ismodulated to a greater extent by the low pressure or vacuum throughconduit 285 and mixture adjustment valve 286 and conduit 289. This inturn causes a lowering of the pressure within chamber 280 and results inthe urging of thediaphragm 276 in an upward direction to decrease thesize of chamber 280 which in turn moves the shutter 304 between thelight source 306 and the photo cell 308. Again, the output of the photocell 308 is diminished which in turn results in a signal to the fuelpump to decease its output. Thus the fuel air mixture is leaned to anextent depending on the temperature and pres sure of the atmospheric airand the setting of the needle valve 288 in the mixture adjustment valve286. When the temperature of the atmospheric air is low, and a richermixture is desired, the bellows 296 is contracted, which moves theneedle valve 294 out of the orifice 292 and causes an increase in theflow of air from aperture 291 through conduit 293 into chamber 280. Theincreased pressure in chamber 280, with respect to the low pressure inchamber 279 from the throat of venturi 252, urges the movement of thediaphragm 276 away from top cover plate 275, and towards lower end wall273, increasing the relative size of chamber 280 and diminishing therelative size of chamber 279. This results in a movement of the shutter304 from between the light source 306 and the photo cell 308 and in turnincreases the output of photocell 308 which in turn v results in anincrease in the output of fuel pump 212.

The force of the fuel pressure within the bellows 281 is balanced by thepressure differential across the diaphragm 276. This pressuredifferential includes the atmospheric pressure, as modulated,vin'chamber 280 and the vacuum pressure at the throat of venturi 252 inchamber 279. The pressure differential across the diaphragm thusdetermines the pressure of the fuel, and thus the fuel flow, the nozzle242 Another embodiment of the sensor unit of FIG. 5 is shown in FIG. 6.The apparatus comprises a lower housing 312 which includes a lower endwall 314 and an aperture 316 in the lower housing312 which communicateswith the vacuum from the throat of venturi 252 as through conduit 283. Acylinder 318 extends or depends downwardly from the lower end wall 314of the lower housing 312. The cylinder includes an interior bore 320which communicates with a source of fuel flow, such as from conduit 213,through an opening or aperture 322. A piston 326 is disposed withinthe-bore 230 and the movement of the piston depends on the fuel pressurewithin the cylinder 318 through aperture 322. A lower diaphragm plate328 is connected to the upper'portion of piston 326. An upper diaphragmplate 330 secures, by appropriate fastening means, the inner peripheryof a diaphragm 332 to lower diaphragm plate 328, for movement therewithin accordance with the movement of piston 326.

The outer periphery of diaphragm 332 is clamped between lower housing312 and upper housing 336. A

lower expansible chamber 334 is defined by-the diaphragm 332 and thelower housing '312. The diaphragm 332 and-the upper housing 336 definean upper expansible chamber335. The upper chamber 335 includes anaperture 338 which vents the upper chamber 335'to atmospheric airpressure, as modulated by vacuum, as through conduits 289 and 293 ofFIG; 5. A rod 340 is secured to upper diaphragm plate 330 for movementtherewith, and the rod 340 supports a shutter 342. As the diaphragm 332moves, in ac'- cordance with the movement of piston 326 and diaphragmplates 328 and 330, the'shutter 342 is also moved. As with similarstructure in FIGS. 4 and 5, the

rod 340 may be omitted and the shutter 342 may be secured directly toplate 330. On opposite sides of upper housing 336 are light source 344and light sensitive means, which may be a photo cell 346. The output oflight responsive means 346 is as described with reference to FIG. 5, andthe movement of the shutter 342 between the light source and the photocell decreases the output of the photo cell to the fuel pump controlamplifiers, such as amplifiers 202 of FIG. 5, and

accordingly decreases the output of .the fuel pump to which it isconnected. The withdrawing of the shutter, or the lowering thereof, frombetween the light source and the photo cell results in an increasedoutput from the photo cell which in turn causes the fuel pump controlamplifiers to signal'the fuel pump to increase its speed and thereforeits output.

The movement of the piston 326 within bore 320 is .directly related tothe pressure of the fuel within the bore 320, as modulated by theventuri vacuum through aperture 316'within chamber 334 and as furthermodulated by the atmospheric air, modulated by the venturi vacuum,through aperture 338 within upper chamber 335. A decrease in thepressure within chamber 334 urges the diaphragm downwardly, as shown inFIG. 6, to decrease the side of chamber 334 to compensate for thelowered pressure therein, which in turn serves to lower the shutter frombetween the light source and the photo cell. Again, the increased lightfrom the light source to the photo cell results in an increased outputfrom photo cell 346 through conductor 347 to the fuel pump controlamplifiers.

Air at atmospheric pressure entering upper chamber 335 through aperture338 urges movement of the diaphragm 332 also in a downwardly direction,as shown in FIG. 6, and in turn results in the same phenomenon-as hasbeen described. If the atmospheric air is modulated by engine vacuum,the pressure within' chamber 355 is in turn modulated and results in acorresponding change in the position of the diaphragm and of the shutterwith respect to the light source and the 7' photo cell. In turn, thisresults in a change in the signal to the fuel pump. When the ignitionsystem of the engine is turned on, light source 344 receives powerthrough conductor 345 from the fuel pump control amplifiers, such asamplifiers 202 of FIG. 5. It will be noted that, as shown in FIG. 6,both the'photo cell and the light source are grounded and only oneconductor is shown extending from the light source and the photo cell toconnect with the fuel pump control amplifiers.

FIG. 7 is a view taken on line 77 of FIG. 6 and illustrates the shutterwith respect to the light source. The rod 340 is shown supporting theshutter 342 thereon. The light source 344 is shown partially obscured bythe shutter 342. Thus, due to the displacement of the shutter 342between the light source 344 and the photo cell 346 (see FIG. 6), thetotal illumination from light source- 342 to photo cell 346 would be Idiminished and the output of the photo cell would be less than itsmaximum as when the full illumination from the light source wereimpinging upon it. As the shutter moves in accordance with movement ofthe diaphragm and the diaphragm plates, the illumination from the lightsource to the photo cell is proportionate- Iy or accordingly varied,resulting in the varied output from photo cell 346 to the fuel pumpcontrol amplifiers through conductor 347, which in turn results in thevariable output of the fuel pump.

It is thus apparent that a fuel injection system has been describedwhich will provide the correct amount of fuel and air to an engine in.the correct proportions under conditions of varying speed and load.Moreover, the system will provide for the efficient u'se'of the fuelwith respect to a decrease. in pollutants discharged or exhausted to theatmosphere by the correct metering of the fuel, by the provision ofvaporized fuel which results in more complete combustion than does fuelwhich is only partially vaporized, and by the withdrawal of fuel fromthe fuel line upon deceleration. The use of various types of expansiblechamber devices provides efiicient and reliable components.

Because of the variable venturi, a broader range of air volumes, andtherefore a broader range of operating ing requirements, withoutdeparting from those princi-- ples. For example, various types ofexpansible chamber devices may be substituted for those shown. Thebellows unit and housing of FIG. 5, identified by reference numerals 296and 298 could be substituted for the bellows units of FIG. 1, identifiedby reference numerals l6 and 94, and vice versa, and other types couldalso be used. Other modifications could be made in the sensor units withrespect to the float'systems, the sensors; themselves, and/or theexpansible chamber devices, such as the diaphragm systems and thebellows units; The appended claims are therefore intended to cover andembrace any such modifications, within the limits only of thetrue'spirit and scope of the invention. This specification and v theappended claims have been I 7 prepared in accordance with the applicablepatent laws fuel conduit means extending from the fuel supply to i theintake manifold means; fuel pump means for providing a variable flow offuel from the fuelsupply to the intake manifold means;

orifice means for varying the flow of fuel to the intake manifold means;sensing means for sensing the flow of fuel; and

control means coupled to said sensing means'for sensing the flow of fueland to the means for sensing the flow of air and tothe fuel pumpmeans tovary the flow of fuel from the fuel pump means.

manifold means further includes venturi means adjacent the air intakechamber.

4. The apparatus of claim 3 in which the venturi means includes aventuri throat.

5. The apparatus of claim 4 in which the venturi means includes meansfor sensing pressure within the intake manifold at the venturi throat.

6. The apparatus of claim 5 in which the venturi means further includesa venturi piston at the venturi throat. Y

7. The apparatus of claim 6 in which the venturi piston is movable insaid venturi throat.

8. The apparatus of claim 7 in which the venturi means further includesmeans responsive to changesin pressure at the intake manifold for movingthe venturi piston in said venturi throat.

9. The apparatus of claim 8 in which the means for moving the venturipiston comprises a cylinder;

a piston movable in said cylinder; and

a piston rod fastened to and extending between said piston and theventuri piston.

10. The apparatus of claim 9 which includes the first means for sensingpressure at the intake manifold coupled to the cylinder.

11. The apparatus of claim 7 in which the intake manifold means furtherincludes throttle means, including a throttle plate located and movablewithin said intake manifold means to further control the flow of air insaid intake manifold means.

12. The apparatus of claim 11 in which the throttle means includes.mechanical linkage connected to the throttle plate for moving thethrottle plate.

13. The apparatus of claim 12 in which mechanical linkage connected tosaid.throttle means is interconnected to the venturi piston forsimultaneous movement of the throttle plate and the venturi piston.

14. The apparatus of claim 13 which includes means for removing fuelfrom said fuel flow to the intake manifold means in response to movementof the mechanical linkage of the throttle means.

15. The apparatus of claim 14 in which the means for removing fuelcomprises:

a cylinder connected to the fuel conduit means;

a piston in said cylinder; and

mechanical linkage connected to said piston and to said mechanicallinkage of the throttle means for moving said piston in response tomovement of said throttle means.

16. The apparatus of claim 13 in which orifice meansv 19. The apparatusof claim 18 in which the orifice means further includes means for movingsaid orifice.

20. The apparatus of claim 18 in which the means for moving said orificeincludes:

a housing;

a diaphragm in said housing;

a rod fastened to and extending between said I said diaphragm, and therod and orifice fastened thereto, in a second direction.

22. The apparatus of claim 21 in which means for biasing the diaphragmin a second direction is responsive to pressure in the intake manifold.

23. The apparatus of claim 7 in which the orifice means includes a rodmovable within the orifice.

24. The apparatus of claim 23 in which the rod I movable within theorifice includes a tapered portion.

25. The apparatus of claim 24 in which the orifice 25' means furtherincludes means for moving the rod within the orifice.

26. The apparatus of claim 25 in which the means for moving the rodincludes means coupled to the rod for movement responsive to themovement of the venturi 3O piston.

27. The apparatus of claim 26 in which the means coupled to the rodresponsive to movement of venturi piston comprises:

a lever coupled to the rod;

spring means biasing the rod in a first direction;

a plate secured to the piston rod; and

a plurality of adjustable members on said plate sequentially bearingagainst the lever in response to movement of the piston rod.

moving the rod further includes means fastened to the lever for movingthe lever in a first direction and in a second direction. I l

29. The apparatus of claim 28 in which the means fastened'to theleverfor moving the in a first direction and in a second direction comprises:

an expansible chamber device including a movable wall; linkage fastenedto the movable wall of the expansi ble chamber and movable therewith;and

fastening means pivotally securing the lever to the linkage.

30. The apparatus of claim 5 in which .the sensingmeans for sensing theflow of fuel includes:

chamber means; means for providing a flow of fuel to said chamber meansfrom said fuel'pump means; and

means for sensing the flow of fuel to said chamber means. I

31. The apparatus of claim 5 in which the sensing means for sensing theflow of fuel includes: I

va housing; I

a first expansible chamber in said housing;

means for providing a flow of fuel from said fuel pump means to thefirst expansible chamber;

a second expansible chamber in said housing;

28. The apparatus of claim 27 in which the means for v means associatedwith the second expansible chamber for sensing the flow of fuel in saidfirst expansible chamber.

32. The apparatus of claim 30 in which means for sensing the flow offuel to the chamber means comprises:

a float in said chamber means; and 1 radio frequency detector means fordetecting the location of said float in said chamber means.

. 33. The apparatus of claim 30 in which the means for sensing the flowof fuel further comprises a float in said chamber means and photo cellmeans for detecting the location of the float in said chamber means.

34. The apparatus of claim 30 in which the means for sensing the flow offuel to the chamber means further comprises means responsive to the flowof fuel for varying the size of the chamber means and means fordetecting the variation in the size of the chamber means.

35. The apparatus of claim 33 in which the chamber I means includes wallmeans defining a chamber, said chamber including an upper portion and alower'por tion, and means for admitting fuel to the lower portion of thechamber.

36. The apparatus of claim 35 in which the means for detecting thelocation of the float comprises:

a light source for providing light;

light responsive means for producing an output in response to light fromthe light source; and

skirt means on the float intermediate the light source and the lightresponsive means for interrupting light from the light source to thelight responsive means in response to vertical movement of the float. v

37. The apparatus of claim 30 in which the chamber means includes: r

a first and second chamber;

a first float in the first chamber;

a second float in the second chamber; and

means for admitting fuel to said first and second chambers to move saidfirst and second floats.

38. The apparatus of claim 37 in which the orifice means areintermediate the first and second chambers.

39. The apparatus of claim 38 in which the means for sensing pressurewithin the intake manifold at the venturi throat is connected to thesecond chamber, and the sensing means for sensing the flow of fuelincludes means for admitting air at substantially atmospheric pressureto the first chamber.

40. The apparatus of claim 39' in which the sensing means for sensingthe flow of fuel comprises a first sensing means for sensing the flow offuel in said first chamber and a second sensing means for sensing theflow of fuel in said second chamber.

4]. The apparatus of claim 40 in which the control means comprises afirst control means coupled to the first sensing means and a secondcontrol means coupled to the second sensingmeans.

42. The apparatus of claim 41 in which the fuel pump means includes afirst fuel pump coupled to said first control means and a second fuelpump coupled to said second control means.

43. The apparatus of claim 42 in' which the sensing means compriseslight responsive photo cell means responsive to the locations of thefloats in the first and second chambers for sensing the flow of fuel.

. The apparatus of claim 30 in which the chamber means comprises:

'a housing; and

expansible chamber means in said housing for receiv-' ing a flow offuel, and said 'eitpansible chamber means varying in size according tothe flow of fuel,

thereto.

45. The apparatus of claim 44 in which the means for sensing the flow offuel to the chamber means comprises meansfor detecting variations in thesize of the chamber means.

46. The apparatus of claim 44 in which the means for detectingvariations in the size of the chamber means 49. The apparatus of claim30 in which the chamber means comprises a pair of housings; expansiblechamber means in each of said housings, and each of said expansiblechamber means varying in size according to the flow of fuel thereto.

50. The apparatus of claim 49 in which the expansible chambermeanscomprises bellows in each of said housings.

51. The apparatus of claim 50 in which means for sensing pressure withinthe intake manifold at the venturi is connected to one. of said'pair ofhousings.

52. The apparatus of claim 50in which the chamber means includes meansfor providing air at substantially atmospheric pressure to the other ofsaid pair of houslngs.

53. The apparatus of claim 52 in which the means for providing air atsubstantially atmospheric pressure includes means for modulating theprovided air with pressure sensed within the intake manifold at theventuri throat.

54. The apparatus of claim 53 in which the means for modulating theprovided air includes;

an orifice connected to the air at substantially atmospheric pressureand to the means for sensing pressure within the intake manifold at theventuri throat;

a needle valve movable in the orifice; and

an expandable bellows connected to the needle valve for moving saidneedle valve in said orifice in response to expansion of the bellows.

i i i i i

1. In an internal combustion engine, fuel injection apparatuscomprising, in combination: a fuel supply; intake manifold means forproviding a flow of air; means for sensing the flow of air in the intakemanifold means; fuel conduit means extending from the fuel supply to theintake manifold means; fuel pump means for providing a variable flow offuel from the fuel supply to the intake manifold means; orifice meansfor varying the flow of fuel to the intake manifold means; sensing meansfor sensing the flow of fuel; and control means coupled to said sensingmeans for sensing the flow of fuel and to the means for sensing the flowof air and to the fuel pump means to vary the flow of fuel from the fuelpump means.
 2. The apparatus of claim 1 in which the intake manifoldmeans includes an air intake chamber for providing a source for the flowof air.
 3. The apparatus of claim 2 in which the intake manifold meansfurther includes venturi means adjacent the air intake chamber.
 4. Theapparatus of claim 3 in which the venturi means includes a venturithroat.
 5. The apparatus of claim 4 in which the venturi means includesmeans for sensing pressure within the intake manifold at the venturithroat.
 6. The apparatus of claim 5 in which the venturi means furtherincludes a venturi piston at the venturi throat.
 7. The apparatus ofclaim 6 in which the venturi piston is movable in said venturi throat.8. The apparatus of claim 7 in which the venturi means further includesmeans responsive to changes in pressure at the intake manifold formoving the venturi piston in said venturi throat.
 9. The apparatus ofclaim 8 in which the means for moving the venturi piston comprises acylinder; a piston movable in said cylinder; and a piston rod fastenedto and extending between said piston and the venturi piston.
 10. Theapparatus of claim 9 which includes the first means for sensing pressureat the intake manifold coupled to the cylinder.
 11. The apparatus ofclaim 7 in which the intake manifold means further includes throttlemeans, including a throttle plate located and movable within said intakemanifold means to further control the flow of air in said intakemanifold means.
 12. The apparatus of claim 11 in which the throttlemeans includes mechanical linkage connected to the throttle plate formoving the throttle plate.
 13. The apparatus of claim 12 in whichmechanical linkage connected to said throttle means is interconnected tothe venturi piston for simultaneous movement of the throttle plate andthe venturi piston.
 14. The apparatus of claim 13 which includes meansfor removing fuel from said fuel flow to the intake manifold means inresponse to movement of the mechanical linkage of the throttle means.15. The apparatus of claim 14 in which the means for removing fuelcomprises: a cylinder connected to the fuel conduit means; a piston insaid cylinder; and mechanical linkage connected to said piston and tosaid mechanical linkage of the throttle means for moving said piston inresponse to movement of said throttle means.
 16. The apparatus of claim13 in which orifice means includes an orifice and a needle valve movablein said orifice to control the flow of fuel therethrough.
 17. Theapparatus of claim 16 in which the orifice means further includesmechanical linkage interconnected between the needle valve and themechanical linkage of the throttle means for providing simultaneousmovement of the needle valve and the throttle plate.
 18. The apparatusof claim 5 in which the orifice means includes housing means coupled tothe fuel conduit means extending between said fuel supply and saidmanifold means, and an orifice movable within said housing means. 19.The apparatus of claim 18 in which the orifice means further includesmeans for moving said orifice.
 20. The apparatus of claim 18 in whichthe means for moving said orifice includes: A housing; a diaphragm insaid housing; a rod fastened to and extending between said diaphragm andsaid orifice; biasing means for biasing said diaphragm, and the rod andorifice fastened thereto, in a first direction.
 21. The apparatus ofclaim 20 in which means for moving said orifice further includes meansfor biasing said diaphragm, and the rod and orifice fastened thereto, ina second direction.
 22. The apparatus of claim 21 in which means forbiasing the diaphragm in a second direction is responsive to pressure inthe intake manifold.
 23. The apparatus of claim 7 in which the orificemeans includes a rod movable within the orifice.
 24. The apparatus ofclaim 23 in which the rod movable within the orifice includes a taperedportion.
 25. The apparatus of claim 24 in which the orifice meansfurther includes means for moving the rod within the orifice.
 26. Theapparatus of claim 25 in which the means for moving the rod includesmeans coupled to the rod for movement responsive to the movement of theventuri piston.
 27. The apparatus of claim 26 in which the means coupledto the rod responsive to movement of venturi piston comprises: a levercoupled to the rod; spring means biasing the rod in a first direction; aplate secured to the piston rod; and a plurality of adjustable memberson said plate sequentially bearing against the lever in response tomovement of the piston rod.
 28. The apparatus of claim 27 in which themeans for moving the rod further includes means fastened to the leverfor moving the lever in a first direction and in a second direction. 29.The apparatus of claim 28 in which the means fastened to the lever formoving the lever in a first direction and in a second directioncomprises: an expansible chamber device including a movable wall;linkage fastened to the movable wall of the expansible chamber andmovable therewith; and fastening means pivotally securing the lever tothe linkage.
 30. The apparatus of claim 5 in which the sensing means forsensing the flow of fuel includes: chamber means; means for providing aflow of fuel to said chamber means from said fuel pump means; and meansfor sensing the flow of fuel to said chamber means.
 31. The apparatus ofclaim 5 in which the sensing means for sensing the flow of fuelincludes: a housing; a first expansible chamber in said housing; meansfor providing a flow of fuel from said fuel pump means to the firstexpansible chamber; a second expansible chamber in said housing; meansassociated with the second expansible chamber for sensing the flow offuel in said first expansible chamber.
 32. The apparatus of claim 30 inwhich means for sensing the flow of fuel to the chamber means comprises:a float in said chamber means; and radio frequency detector means fordetecting the location of said float in said chamber means.
 33. Theapparatus of claim 30 in which the means for sensing the flow of fuelfurther comprises a float in said chamber means and photo cell means fordetecting the location of the float in said chamber means.
 34. Theapparatus of claim 30 in which the means for sensing the flow of fuel tothe chamber means further comprises means responsive to the flow of fuelfor varying the size of the chamber means and means for detecting thevariation in the size of the chamber means.
 35. The apparatus of claim33 in which the chamber means includes wall means defining a chamber,said chamber including an upper portion and a lower portion, and meansfor admitting fuel to the lower portion of the chamber.
 36. Theapparatus of claim 35 in which the means for detecting the location ofthe float comprises: a light source for providing light; lightresponsive means for producing an output in response to light from thelight source; and skirt means on the float intermediate the light sourceand the light responsive means for interrupting lIght from the lightsource to the light responsive means in response to vertical movement ofthe float.
 37. The apparatus of claim 30 in which the chamber meansincludes: a first and second chamber; a first float in the firstchamber; a second float in the second chamber; and means for admittingfuel to said first and second chambers to move said first and secondfloats.
 38. The apparatus of claim 37 in which the orifice means areintermediate the first and second chambers.
 39. The apparatus of claim38 in which the means for sensing pressure within the intake manifold atthe venturi throat is connected to the second chamber, and the sensingmeans for sensing the flow of fuel includes means for admitting air atsubstantially atmospheric pressure to the first chamber.
 40. Theapparatus of claim 39 in which the sensing means for sensing the flow offuel comprises a first sensing means for sensing the flow of fuel insaid first chamber and a second sensing means for sensing the flow offuel in said second chamber.
 41. The apparatus of claim 40 in which thecontrol means comprises a first control means coupled to the firstsensing means and a second control means coupled to the second sensingmeans.
 42. The apparatus of claim 41 in which the fuel pump meansincludes a first fuel pump coupled to said first control means and asecond fuel pump coupled to said second control means.
 43. The apparatusof claim 42 in which the sensing means comprises light responsive photocell means responsive to the locations of the floats in the first andsecond chambers for sensing the flow of fuel.
 44. The apparatus of claim30 in which the chamber means comprises: a housing; and expansiblechamber means in said housing for receiving a flow of fuel, and saidexpansible chamber means varying in size according to the flow of fuelthereto.
 45. The apparatus of claim 44 in which the means for sensingthe flow of fuel to the chamber means comprises means for detectingvariations in the size of the chamber means.
 46. The apparatus of claim44 in which the means for detecting variations in the size of thechamber means comprises: a diaphragm within said housing adjacent saidexpansible chamber means and movable therewith; a shutter plate on saiddiaphragm and movable therewith; light responsive means adjacent theshutter plate for producing an output in response to movement of theshutter plate.
 47. The apparatus of claim 46 in which the expansiblechamber means comprises a bellows.
 48. The apparatus of claim 46 inwhich the expansible chamber means comprises a cylinder and a piston insaid cylinder.
 49. The apparatus of claim 30 in which the chamber meanscomprises a pair of housings; expansible chamber means in each of saidhousings, and each of said expansible chamber means varying in sizeaccording to the flow of fuel thereto.
 50. The apparatus of claim 49 inwhich the expansible chamber means comprises bellows in each of saidhousings.
 51. The apparatus of claim 50 in which means for sensingpressure within the intake manifold at the venturi is connected to oneof said pair of housings.
 52. The apparatus of claim 50 in which thechamber means includes means for providing air at substantiallyatmospheric pressure to the other of said pair of housings.
 53. Theapparatus of claim 52 in which the means for providing air atsubstantially atmospheric pressure includes means for modulating theprovided air with pressure sensed within the intake manifold at theventuri throat.
 54. The apparatus of claim 53 in which the means formodulating the provided air includes: an orifice connected to the air atsubstantially atmospheric pressure and to the means for sensing pressurewithin the intake manifold at the venturi throat; a needle valve movablein the orifice; and an expandable bellows connected to the needle valvefor moving said needle valve in said orifice in response to expansiOn ofthe bellows.